Semiconductor imaging arrays form the basis of modern digital cameras. A semiconductor imaging array is an imaging array of pixel sensors in which each pixel generates a signal that measures the amount of light in a predetermined band of wavelengths that strikes the pixel within the exposure time. For example, color imaging arrays typically utilize three different types of pixel sensors that measure the light intensity in three bands, typically red, green, and blue. The individual sensors can be constructed from a single sensor design and wavelength filters that determine the portion of the incident light spectrum that is incident on the sensors. In other sensors, the different sensors have different wavelength sensitivities and filters are not needed.
Originally, digital cameras utilized sensor arrays in which the different sensors are arranged on the sensor surface along side of one another. As a result, the light intensity measured at any given location in the array only provides information on the intensity of light in one band at that location. The intensity of light in another band at that location must be inferred from the sensors for that band in the vicinity of the location in question. Such interpolation limits the resolution of the imaging array and can introduce color artifacts.
Imaging arrays in which multiple detectors are located at each location are also known. In these arrays, several detectors are stacked vertically in the array at each location. Each detector measures the light intensity in a different fixed band that depends on the depth of the detector from the surface of the array. The bands measured by the detectors are fixed at manufacture, and hence, cannot be altered in the field.